随机数RandomValuePropertySourceEnvironmentPostProcessor

随机数生成

public class RandomValuePropertySourceEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {
    public static final int ORDER = Ordered.HIGHEST_PRECEDENCE + 1;
    private final Log logger;
    public RandomValuePropertySourceEnvironmentPostProcessor(Log logger) {
        this.logger = logger;
    }
    @Override
    public int getOrder() {
        return ORDER;
    }
    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        RandomValuePropertySource.addToEnvironment(environment, this.logger);
    }
}

RandomValuePropertySource就是生成随机数的工具source

public class RandomValuePropertySource extends PropertySource<Random> {
    public static final String RANDOM_PROPERTY_SOURCE_NAME = "random";
    private static final String PREFIX = "random.";

    public RandomValuePropertySource() {
        this(RANDOM_PROPERTY_SOURCE_NAME);
    }
    public RandomValuePropertySource(String name) {
        super(name, new Random());
    }
    @Override
    public Object getProperty(String name) {
        if (!name.startsWith(PREFIX)) {
            return null;
        }
        return getRandomValue(name.substring(PREFIX.length()));
    }

    private Object getRandomValue(String type) {
        if (type.equals("int")) {
            // random.int
            return getSource().nextInt();
        }
        if (type.equals("long")) {
            return getSource().nextLong();
        }
        String range = getRange(type, "int");
        if (range != null) {
            // random.int(0,10) 生成[0,10)之间的整数
            return getNextIntInRange(Range.of(range, Integer::parseInt));
        }
        range = getRange(type, "long");
        if (range != null) {
            return getNextLongInRange(Range.of(range, Long::parseLong));
        }
        if (type.equals("uuid")) {
            return UUID.randomUUID().toString();
        }
        return getRandomBytes();
    }
}

该PropertySource主要处理SpringCloud配置中随机数的生成，如application.properties配置文件中使用如下配置

#随机端口
server.port=random.int
#范围随机数
user.age=random.int(0,100)
#long型
app.id=random.long